1. Field of the Invention
The present invention generally relates to roof penetrating systems such as skylights on buildings, and more particularly relates to skylight and similar systems which are installed on metal panel roofs having rib elevations.
2. Description of Related Art
Various systems involving curb structures have heretofore been used for inserting skylights and smoke vents into metal panel roofs on buildings. The most commonly used skylighting systems are those which incorporate translucent or transparent layers held in a framework that penetrates the roof structure, so as to allow ambient daylight into the building.
In the past, roof penetrating installations have required a complex structure beneath the roofing panels in order to support a roof curb to which the skylight was attached. Skylight curbs are generally in the form of a preassembled box structure fixed within a roof cutout or opening. However, the retrofitting of such curb systems into existing roof structures is problematic.
U.S. Pat. No. 4,296,581, to Heckelsberg, issued Oct. 27, 1981, provides an example of a roofing structure of the type which is constructed of a series of metal panels having flanges that interlock when the panels are laid side by side and which are subsequently tightly seamed together to convert the individual panels into an integrated roof-forming membrane. This roof structure is mounted to the purlins in the roof with clips that permit the panels to expand or contract in response to temperature and pressure changes, thereby minimizing roof stressing.
U.S. Pat. No. 4,703,596, to Sandow, issued Nov. 3, 1987, and titled “Grid Skylight System”, provides a grid skylight support apparatus that includes prefabricated grid row frames, each of which forms a number of connected beam supports which define a number of bays. Each bay has a skylight curb formed by the upper flanges of the beam supports to receive a preassembled skylight unit. The sides of each grid row frame provide a mating edge that can register with the mating edge of an adjacent grid row frame during assembly. The skylights have peripheral support skirts that register upon each bay and a light-transmitting skylight panel to cover the peripheral support. Cross gutters on each grid row frame, which are positioned between adjacent skylights, extend at an angle toward the mating edge of the grid row frame for carrying rainwater to a main gutter channel formed by field-assembly of the mating edges of two adjacent grid row frames. The main gutter channel includes a pair of longitudinally extending gutter sections, each of which has a main gutter channel surface with a lower elevation than the elevation of the cross flow channel. Fasteners assemble the grid row frame mating edges together in a continuous seal to prevent rainwater leakage at the mating edges of adjacent grid row frames.
U.S. Pat. No. 4,520,604, to Halsey, et al., issued Jun. 4, 1985, and titled “Skylight Structure”, teaches a curb structure that is dimensioned to be passed through an opening in a roof and then attached in moisture impervious relation to the roof from within a building interior. A skylight assembly including a frame and light transmitting member secured to the frame is dimensioned to be passed through the opening and attached in a sealing engagement to the curb structure from within the building interior for covering the opening. The skylight assembly is then secured to the rafters and headers at an interior location. The frame includes upper and lower clamping jaws and spaced fulcrum links attached to the jaws for clamping the light transmitting member thereto. The lower clamping jaw includes a channel which engages and is interlocked with the curb structure.
Other skylight systems, as contemplated in U.S. Pat. No. 4,470,230, by Weisner, provide a prefabricated skylight support curb that is formed to be a protective packaging for the skylight during shipment and then used as a curb for mounting the skylight in a roof. A prefabricated skylight support curb for supporting a skylight thereover has a bottom flange, angled upright sides, and a top lip around the top of the sides which form an opening through the curb. A skylight is adapted to cover the opening formed by the skylight support curb when the skylight is installed, and has a domed portion, an angled curb portion extending from the dome portion and a drip edge on the curb portion. The skylight curb portion is shaped to fit over a portion of the prefabricated skylight support curb. The skylight and skylight support curb are shaped so that they can nest together in stacks of skylights and curbs to protect the skylights during shipping and storing.
In another skylight system, as contemplated in U.S. Pat. No. 3,791,083, by Sandow, et al., prefabricated multiple dome units or skylights and composite thereof are provided, wherein each multiple dome unit has several domes of transparent or translucent material mounted together on a common frame, and wherein means are provided for assembling a plurality of such dome units into a composite thereof on a building, with the units lapped and inter-fitted so as to provide a continuous drainage system discharging to the exterior of the units in the composite assembly.
In yet another skylight system, as contemplated in U.S. Pat. No. 4,621,466, by Sanneborn, et al., a flashing frame is described for roof windows to be installed adjacent to each other with edges facing each other in the installed position. A connecting flange of the upper flashing members extends beneath the roofing and, if need be, with lower flashing members and required intermediary flashing members, obliquely outwardly bent connecting webs, each with a connecting bar with supporting webs which rearwardly engage the connecting webs, are adjacent the width of the installation distance and are obliquely bent inwardly on both sides. At least one inner projection engages between the facing corner edges of the connecting webs in the installed position, thus maintaining the corner edges at the installation distance.
In today's world of mandated energy efficiency in all types of buildings the metal building industry needs a more economical and less detrimental way to use skylights and smoke vents to daylight buildings. To ensure adequate daylighting, however, typical skylight and smoke vent installations require multiple roof penetrations that cut through and remove plural major elevations in standing seam and other raised rib metal panel roof profiles. Such curbs create multiple opportunities for water to enter the interior of the building, due to multiple curb locations and the widths of the curbs, as well as the challenge to effectively seal the roof at the upper ends of such curbs.
The traditional curb constructions and methods of attachment in most cases require a complicated support structure to be installed below the roof panel, which can restrict movement associated with the thermal expansion and contraction of the metal roof due to temperature changes and the like.
None of the prior approaches have been able to provide an installation system for multiple skylights that accomplishes all the goals of economy and simplicity of installation and that will work equally well for new buildings and as a retrofit in existing buildings.